Spacers for field emission displays are known in the art. Prior art spacers include structural elements which must be individually placed and aligned. Individual placement of these elements adds complexity and time to the fabrication of field emission displays.
Prior art spacers also require affixation to the display plates in the active region of the display. The active region of the display includes the electron emitting elements, which may include Spindt tips, and the light-emitting phosphor elements. A disadvantage of using affixants in the active region is a high risk of damage to these active elements during the affixing process.
Field emission displays require spacers having a high aspect ratio. The aspect ratio is the ratio of the height of the spacer relative to the width. In order to make the spacer invisible to the viewer, the spacer needs to have a thickness that will fit within the region available between adjacent pixels. This distance is equal to about 100 micrometers, which is about one-tenth of the distance between the display plates.
Prior art field emission displays further include gettering materials for the removal of contaminant gases. The configurations of prior art getters for field emission displays add unnecessary weight and volume to the device. In one prior art scheme, the gettering material is housed in a vacuum chamber, behind the cathode plate. The vacuum chamber is defined by an additional backplate, which adds unnecessary weight and volume to the display.
Accordingly, there exists a need for an improved spacer structure for a field emission display which does not require affixation within the active region of the display, which is simple to handle and align, and which provides high aspect ratio spacers. There further exists a need for an improved getter configuration which reduces the weight and volume of the display.